Enabling is a term used for laws that confer legal powers to someone or something. An enabling act makes it possible for authorities to take action.
One meaning of the verb enable is "to provide with legal powers," so the adjective formed by adding -ing gets used to describe legislation that has that empowering effect. When new American states were formed out of frontier territories, they could either organize statehood themselves, or they could be admitted into the Union through an "enabling act" of Congress.
